How warfare shaped human evolution

From the newscientist.com article:
It’s a question at the heart of what it is to be human: why do we go to war? The cost to human society is enormous, yet for all our intellectual development, we continue to wage war well into the 21st century. 

Now a new theory is emerging that challenges the prevailing view that warfare is a product of human culture and thus a relatively recent phenomenon. For the first time, anthropologists, archaeologists, primatologists, psychologists and political scientists are approaching a consensus. Not only is war as ancient as humankind, they say, but it has played an integral role in our evolution. 

The theory helps explain the evolution of familiar aspects of warlike behaviour such as gang warfare. And even suggests the cooperative skills we’ve had to develop to be effective warriors have turned into the modern ability to work towards a common goal.
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If group violence has been around for a long time in human society then we ought to have evolved psychological adaptations to a warlike lifestyle. Several participants presented the strongest evidence yet that males – whose larger and more muscular bodies make them better suited for fighting – have evolved a tendency towards aggression outside the group but cooperation within it. “There is something ineluctably male about coalitional aggression – men bonding with men to engage in aggression against other men,” says Rose McDermott, a political scientist at Stanford University in California.

Read the article here.

See Ancient Rome in 3D

Google Earth has a new feature that is very interesting.

In the Ancient Rome 3D layer, you can:
Fly into Rome as it looked in 320 A.D.
Tour the interior of famous buildings.
Visit the sites in 3D such as the Roman Forum, Colosseum and the Forum of Julius Caesar.
Learn about how the Romans lived.

See it here.

Telomeres and Human Extinction

Human chromosomes (grey) capped by telomeres (white) -Wikipedia

From the guardian.co.uk article:
Like plastic tips on the end of shoelaces, all eukaryotic species have telomeres on the end of their chromosomes to prevent instability. However, cells seem to struggle to copy telomeres properly when they divide, and very gradually the telomeres become shorter.
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Once a telomere becomes critically short it causes diseases related to chromosomal instability, or limited tissue regeneration, such as cancer and immunodeficiency. “The shortening of telomeres between generations means that eventually the telomeres become critically short for a particular species, causing outbreaks of disease and finally a population crash,” says Stindl. “It could explain the disappearance of a seemingly successful species, like Neanderthal man, with no need for external factors such as climate change.”
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Current estimates suggest telomeres shorten only a tiny amount between each generation, taking thousands of generations to erode to a critical level. Many species can remain stable for tens to hundreds of thousands of years, creating long flat periods in evolution, when nothing much seems to happen.
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Indicators for human extinction

Human telomeres are already relatively short. Are we likely to become extinct soon?

1: Cancer
Cancer incidence does seem to have increased, but it is hard to say whether this is due to longer lifespans, more pollution, or telomere erosion. The shortest telomere in humans occurs on the short arm of chromosome 17; most human cancers are affected by the loss of a tumour suppressor gene on this chromosome.

2: Immunodeficiency
Symptoms of an impaired immune system (like those seen in the Aids patients or the elderly) are related to telomere erosion through immune cells being unable to regenerate. Young people starting to suffer more from diseases caused by an impaired immune system might be a result of telomere shortening between generations.

3: Heart attacks and strokes
Vascular disease could be caused by cells lining blood vessels being unable to replace themselves – a potential symptom of telomere erosion.

4: Sperm counts
Reduction in male sperm count (the jury is still out on whether this is the case) may indicate severe telomere erosion, but other causes are possible.

Read the article here. (This article was written in 2004)

Moer about Telomeres here.